Post-Install and Use Guide, Wood-Fired

First Use Setup

1. Sauna Stones

Wash your sauna stones with clean water to remove any dust or debris.
Load the larger stones down the sides of the heater first, then fill over the top with a mix of larger and smaller stones.
Stack loosely, not tightly. You want plenty of airflow between the stones. All of your heat has to rise up through that stack, so the gaps are what give you an even, efficient heat.
Do not overfill. Keep the stones within the cage and avoid stacking above the designated area.
Avoid jamming stones in place. Tight stacking blocks airflow and makes the sauna slower to heat and harder to hold temperature.

2. Burn Off Manufacture Residue

Your heater has a high temperature coating on it that needs to cure, and the sauna has a little manufacturing residue to burn off.

Get a small fire going and close the heater door.
Leave the sauna door open, and do not sit in the room while it burns off.
Let it run through about three small loads of wood, which takes roughly two to three hours.
You will notice a distinct smell during this time.
Your sauna is ready to use once the smell has completely gone. If it is still noticeable the next time you light it, run it through another load or two.

3. Heating for the First Time

Light your fire and allow around 40 minutes for the sauna to reach temperature.
The thermostat for a wood fired heater is the amount of wood you have burning!
Start with a small fire to gauge the heat generated from that and then build up. Please note that wood-fired heaters can get heated very nicely with a small fire usually.
Watch the thermometer on the wall for your first few sessions. You will quickly get a feel for how much wood gets you where you want to be, and how long it holds.
Once you have worked out the temperature you prefer with the wood load that can be your standard. It will be a fun experiment that involves having a sauna!

Lighting and Running the Fire

1. What to Burn

Dry, seasoned hardwood. Dry wood is the single biggest thing between you and a hot sauna.
Start with pine or another light wood to get the fire going, then move to small split hardwood once it has taken hold.
Green or wet wood burns cool, makes smoke and tars up the inside of your flue. If the wood hisses or the ends look damp, it is not ready.
Never burn treated, painted, laminated or composite timber, driftwood, or anything with glue or plastic in it.
No petrol, no solvent firelighters, no accelerants of any kind, and no rubbish.
Split it short enough to sit comfortably inside the firebox. A lot of bagged firewood comes longer than you need.

2. Lighting It

Clear any old ash out first. The fire needs air through the firebox and old ash blocks it.
Start small, with the driest and smallest pieces, and light it so it takes quickly.
IMPORTANT Close the heater door once the fire is going. It stays shut from then on.
Build up in batches as it establishes, increasing the size of the wood as you go. Add more only when the flames die down, and never fill the firebox right up.
Start smaller than you think. These heaters are very powerful, and it is far easier to build a fire up than to pull one back.

3. Loading

If your firebox is internally fed, you load it from inside the sauna. Open the door slowly, add the wood, and close it again. Keep towels and anything else off the floor nearby.

If your firebox is externally fed, the door comes through the wall and you load from outside. You never open the firebox inside the room, and the wood and the mess stay out of the sauna entirely.

4. Through Your Session

Top up with one or two pieces as the fire burns down, rather than letting it go out and starting again.
How much wood is in there is your temperature control. A smaller fire held steady is usually more comfortable than a big one.
A quick check on how well it is burning: look at the smoke. Colourless means it is burning cleanly. Dark or brown smoke means it is not, and that is what tars up a flue.
Keep the air vents open the whole time.

5. Shutting Down

Stop adding wood towards the end of your last round and let the fire burn down on its own. Never put water on it to put it out.
Never leave the sauna with a fire still burning in it.
Leave the air vents open afterwards so the room dries out, and leave the door open for a while.

Ongoing Use and Routine

1. Preparing and Starting Your Session

Light the fire earlier than you would switch a heater on. Everything else below is the same as any sauna.

Clothing: Choose natural fabrics such as cotton. Avoid synthetic materials or garments with metal clips. Remove watches and smart watches, they can heat up quickly and may not tolerate the high temperatures.

Personal care: Avoid perfumes, lotions or body oils before entering. These can seep into the timber and leave marks, and the chemicals in scented products may become more potent when heated, which is not ideal for air quality or skin when your pores are open in response to the heat.

Seating: Using a towel will help protect the timber from sweat marks. You may also choose to have the bench oiled at installation if you prefer to sit directly on the timber.

Ventilation: Keep the air vents open throughout your session. With a wood fire this is a safety requirement, because the fire needs a supply of fresh air to burn cleanly, and that same airflow is what creates löyly, the Finnish term describing the natural process of ventilation and heat circulation created when water meets the stones. Never block, cover or close a vent.

Hydration: Drink water before, during and after each session.

Sauna hat: Wearing a sauna hat helps protect your head and hair from overheating and keeps your body temperature balanced.

Switch off: We recommend leaving all devices outside the sauna so you can completely switch off and enjoy the quiet moments your sauna offers.

2. Pouring Water on the Stones

You may choose to add a few drops of essential oil (lemon, peppermint or eucalyptus) into a small ladle of water before pouring.
Pour a small ladle of water at arm's length over the stones to create steam. This will be hot, so stand back to avoid the initial rush of heat.
Allow the intensity of the heat to envelop you, taking a moment to settle and focus on your breath.
You may wish to add a second pour after a minute or two, or simply enjoy the dry heat. Both are fine.
Some people prefer not to pour water at all, while others like to do it a few times during their session.
It is important to avoid overpouring. Use a small ladle, pour it over the stones rather than down the side, and keep the water on the stones and off the firebox and the flue.

3. Essential Oils (Optional)

Add 1 to 2 drops of the provided essential oils (lemon, peppermint or eucalyptus) to your ladle of water before pouring it on the stones.
Never drop oils directly onto the hot stones, always dilute them in water.
These oils can enhance relaxation, open the airways and refresh the mind.

4. Breathing and Session Flow

Aim for easy, steady breathing, ideally through your nose, or light mouth breathing if that feels easier.
Stay in the sauna for about 10 to 20 minutes per round. Two or three rounds adds up to roughly 15 to 60 minutes in the heat across a session. Come out as soon as it stops feeling comfortable.
You can take a short break on the lower bench between rounds or during a session, the temperature is milder and allows your body to adapt gradually.
Staying a moment longer than feels easy, as long as you remain comfortable and stable, can help your body build resilience over time.
Follow with a cold exposure (ice bath, pool or shower), then return to the sauna.
Repeat for 2 to 3 cycles as time and preference allow.

Daytime sessions: finish on cold for an energising effect.

Evening sessions: finish on warm to promote relaxation and sleep. Stop feeding the fire towards the end and let it carry you out.

Fire Safety

You have a real fire in the room, so a handful of things matter more than anything else in this guide. None of it is complicated.

Never leave the heater door open and walk away. Open it to load, then close it again, and keep it shut any time you are not standing at it.
Never leave the sauna with a fire still burning in it.
Keep a bucket of water in the sauna. Your ladle bucket will do the job, as long as there is enough water in it to put out an ash or an ember that falls out of the heater.
Keep a fire extinguisher nearby. Not inside the sauna, but somewhere close by that you can get to. Bunnings carry them.
Keep the area around the heater clear. No towels, robes or anything else within the clearances we set at installation.
The heater, its door, the cage and the flue all get extremely hot, and the flue stays hot well after the fire is out. Do not touch them during or after use, and keep children away from them.
Keep the air vents open. They feed the fire and they are what makes it draw properly. A fire starved of air draws badly, and a badly drawing fire is what pushes smoke back into the room instead of up the flue. A wood fire also produces carbon monoxide, which you cannot see or smell, so never run it with the sauna sealed up.

Smoke

A bit of smoke while you are lighting it is normal and pretty much unavoidable. Once the fire has taken hold it should draw cleanly, pulling air in through the vents and sending everything out through the flue.

What is not normal is smoke coming off the flue inside the sauna. If you see that, or you can smell smoke in the room once the fire is established, get out and open the door, let the fire burn down, and give us a call before you use it again.

Sauna Safety

Always pay attention to how you feel. If you experience dizziness, light-headedness or nausea, leave the sauna immediately and cool down. The same goes for feeling headachy or unwell in a way that does not feel like the heat.
Avoid alcohol before or during sauna use. This matters more with a wood fire, because you are managing an open fire as well as yourself.
Children can enjoy the sauna when accompanied by an adult. Keep temperatures moderate and sessions shorter. A sauna hat can help protect a child's head from excess heat.
If you are pregnant, check with your doctor first, keep sessions moderate and brief, and always listen to your body.

Sauna Stone Care

Your sauna stones are essential to performance and safety. Regular care helps your heater work efficiently, maintains even heat, and extends its lifespan.

1. Why Stone Care Matters

Over time, stones can crack, crumble or compact under heat and steam. This restricts airflow through the heater and can lead to uneven heating or overheating.

2. Inspect Your Stones Regularly

Check your stones a couple of times a year, or more often with frequent use.
Remove any stones that are cracked, crumbled or have sharp edges.
Rinse or brush away accumulated dust or grit before replacing.

3. Re-stack for Proper Airflow

Larger stones down the sides and at the bottom for stability, with a mix of larger and smaller over the top.
Create small air gaps between them.
Do not pack them tightly. Good ventilation through the stones is what gives you a safe and efficient heat.

4. Maintain and Refresh Stones

At least once a year, when the heater is completely cool, remove the stones, rinse them clean, and discard any that are broken or crumbling.
Restack with clear air gaps and top up with fresh stones only as needed to keep the heater properly filled.
A full replacement is not usually necessary unless many stones are degraded.
Regular maintenance prevents heater strain and helps maintain smooth, even heat and ventilation.

Ash and Flue Care

1. Ash

Clear the ash out before each fire, not just when it builds up. The heat depends on air moving through the firebox, and ash is what blocks it.
Only ever clear it when the fire is completely out and the ash is cold, which can take overnight. Wear gloves.
Put ash into a metal container with a lid, and keep it outside and away from anything that can burn. Never into a plastic bin, a cardboard box or a garden bag. Ash holds live embers for days after a fire looks dead.

2. The Flue

Have the flue swept and checked once a year. Burning dry wood and running the fire properly hot keeps build-up down, but it does not remove the job.
Check the spark arrestor is clear and in place.
Look at where the flue comes through the roof when you do your yearly oiling, and check the flashing is sound and nothing has worked loose.

Sauna Cleaning and Maintenance

Regular cleaning keeps your sauna fresh, hygienic and performing well for years to come.

Before you start

Let the sauna cool completely before you clean it. Never clean a hot sauna, and never clean the heater or the stones while there is any heat in them. With a wood fire that means waiting until the firebox and the flue are cold, which can take overnight.

What to avoid

Bleach, ammonia and harsh household cleaners. The timber absorbs them, and when the sauna heats up they can release unpleasant fumes.
Scented sprays and air fresheners, for the same reason.
Cleaning products anywhere near the heater or the stones. Water only on the stones.
Pressure washers, or hosing the sauna out. It soaks the timber and leads to warping, cracking and mould.
Abrasive scourers and wire brushes, which scratch the timber.
Leaving wet towels inside, which traps moisture and encourages mildew.

The routine

After each use

Wipe any visible moisture or sweat from the benches and backrests with a damp cloth. No cleaners needed.
Leave the door open for 20 to 30 minutes so the moisture can escape and the timber dries properly.

Weekly

Let the sauna cool completely before you start.
Sweep or vacuum the floor, including underneath the benches.
Wipe the benches, backrests and door handle with a soft cloth dipped in warm water, working with the grain. Wring the cloth out well, the aim is damp, not wet.
Finish with a dry cloth and leave the door open to air dry.

Every month or two

Use a sauna-specific cleaner, or mix one part white vinegar to ten parts warm water.
Apply to the benches, backrests and lower walls with a soft cloth or brush, working with the grain.
Wipe off with a cloth dampened in clean water to remove any residue.
Sweep up any bark, splinters and ash around the heater while you are there.
Air it out with the door open, ideally for a few hours.

Regular light cleaning is far better for the timber than occasional deep scrubbing.

For stubborn sweat marks, mildew, the glass door and the full kit list, see our Sauna Care and Cleaning Guide.

Internal Timber Care

Regular light maintenance will help keep the timber looking and feeling fresh.
For occasional refresh or additional protection, Livos Oils are linseed-based and designed to nourish and protect the timber without synthetic additives or odours.
Always apply lightly with a soft cloth or sponge, allow it to absorb, and wipe away any excess.
You can also use a timber-specific paraffin oil, only using high-purity, food-grade options, often labelled white mineral oil or liquid paraffin BP or USP grade.
Paraffin oil can help reduce moisture absorption and maintain colour.
Both natural oil (Livos) and paraffin will slightly darken the timber.

External Timber Care

For external protection of outdoor saunas, the timber will require oiling.
Saunas are oiled at installation, and a second coat should be applied a few days later.
Every 12 to 18 months, reapply a light coat to maintain protection and colour.
We recommend and use Livos Oils, a natural, linseed-based oil that provides long-lasting weather and UV protection.
While you are up there, check the flue flashing and the roof penetration, and clean off any soot staining around it.

The Science and Expert Insights

If you would like to explore the science behind sauna and cold exposure, these expert discussions are a great place to start.

Rhonda Patrick, Sauna Use and Building Resilience to Stress. Listen on Spotify
Peter Attia with Rhonda Patrick, The performance and longevity paradox of IGF-1, ketogenic diets, the health benefits of sauna, and more. Listen on Spotify
Andrew Huberman with Dr Susanna Søberg, How to Use Cold and Heat Exposure to Improve Your Health. Listen on Spotify

Ongoing Care

Keep the vents open during every session, for safe combustion and for airflow.
Burn dry, seasoned hardwood only.
Wipe benches and backrests after each use with a damp cloth to remove sweat and moisture.
Clear cold ash into a lidded metal container before each fire, and keep it outside.
Once a week, clean benches, walls and the floor with warm water and a mild natural detergent or sauna-specific cleaner.
Every month or two, give your sauna a deeper clean. Gently scrub the timber surfaces with warm water and a mild solution, rinse well, and allow to dry completely.
At least once a year, inspect your stones and restack them, replacing or topping up as needed.
Have the flue swept and checked once a year, and keep the spark arrestor clear.
For outdoor saunas, re-oil the exterior timber with a natural oil (we recommend Livos) every 12 to 18 months, and check the flue flashing at the same time.
Keep the vents clear at all times for airflow.

Contact

Please contact support@peaksaunaice.au with any questions.

Thanks

Eva and Andrew

Happy Sauna-ing